In a leaf switch, a leaf contact piece which is extended toward a cam body is displaced by a cam part of the cam body to perform “ON” and “OFF” operation. In order to perform various switching operations by using the leaf switch, it is conceivable that a plurality of cam parts are formed in one piece of cam body in a multistage shape in a height direction which is perpendicular to its moving direction, and tip end sides of a plurality of leaf contact pieces which are linearly extended toward respective cam parts are abutted with the respective cam parts.
Further, an ice making device has adopted a structure in which a raking member is rotationally driven by a drive unit to discharge ice pieces from an ice tray. In this case, when an ice adhering force between the ice tray and ice pieces is large, ice pieces cannot be discharged. Therefore, an ice making unit provided with a heater at the vicinity of the ice tray has been adopted (see, for example, Japanese Patent Laid-Open No. 2003-143808).
Further, a detecting method for detecting ice amount in an ice storage part structured in an ice making device has been commonly known in which an ice detecting lever is driven in an approaching direction to the ice storage part to detect whether the ice detecting lever is disturbed by ice pieces in the ice storage part or not by using a lever position detecting mechanism. In order to structure the lever position detecting mechanism as described above, an operation of the ice detecting lever is required to be transmitted to a switch through a cam mechanism to detect a position of the ice detecting lever on the basis of “ON” and “OFF” operation of the switch. In this case, a cam face of the cam mechanism at a position corresponding to a timing when the switch performs the “ON” and “OFF” operation is formed in a slant face and thus a contact of the switch is gradually moved closer and moved away.
When a plurality of leaf contact pieces is linearly extended toward a plurality of cam parts formed in a multistage, height positions of the leaf contact pieces are different form each other and thus a structure of a contact piece holding part for holding the base end side of the leaf contact pieces becomes complicated. For example, in a case that a structure is to be adopted in which the contact piece holding part is formed with contact piece holding grooves and the leaf contact pieces are held in a state that the base end sides of the leaf contact pieces are inserted into the contact piece holding grooves, a plurality of contact piece holding grooves whose bottom parts are formed at different height positions is required. Further, when the base end sides of the leaf contact pieces which are inserted into the contact piece holding grooves are pressed in a height direction to be held, a pressure member in a complicated shape is required. Therefore, a lot of labor is required in assembling work of the leaf switch and a high degree of positional accuracy is difficult to be obtained for the leaf contact pieces.
In the above-mentioned ice making device, when a water-supply part is structured to the ice tray and a micro switch for controlling a water-supply time period from the water-supply part to the ice tray is provided, water supply can be also performed automatically. In addition, if a water-supply time period can be adjusted, amount of water supplied to the ice tray is adjusted. Therefore, size of ice can be changed arbitrarily. However, in order to adjust a timing of a micro switch which is turned on and off, mounting position of the micro switch is required to be changed and thus adjustment of water supply time period (amount of water supply) is not performed easily.
On the other hand, when a leaf switch is turned on and off by a cam face, a contact of the leaf switch gradually comes close or moves apart. Therefore, an unstable region is occurred which is not clearly distinguished between a state that contacts have come into contact with each other and a state that the contacts have moved apart from each other and thus various electric malfunctions may occur. Accordingly, when a leaf switch is used as a switch which is operated by a cam mechanism, electric malfunctions may be easily occurred. On the contrary, a micro switch is capable of turning immediate “ON” and “OFF”. However, a micro switch is expensive and largely affected by mounting error and operational position error and thus ice amount cannot be detected with a high degree of accuracy.